The present invention relates generally to a timing device, more particularly to a timely adjustment device for the control of the fuel injection start for a motor vehicle internal-combustion engine. Preferred embodiments of the invention relate to an arrangement for controlling the fuel injection start, wherein a connection; having one section fixed to move with a primary part of the transmission and another section positioned to move with a secondary part of the transmission, effects a circumferential rotation of the secondary part with respect to the primary part.
Based on U.S. Pat. No. 3,973,540, a hydraulic adjusting device is known where the rotating movement between the primary part and the secondary part is forced as a function of the admission of pressure medium to the piston via diagonally extending slot guiding means.
Also, a hydraulic adjusting device is known from U.S. Pat. No. 3,685,499 where the axially acting piston is connected with the primary part by an expensive toothing. In this case, the toothing is to permit a rotationally stable connection as well as a relative movement in an axial direction between the primary part and the piston. For the relative rotational movement between the primary and the secondary part, balls are provided as transfer members which are guided in diagonally extending guide grooves.
The invention is based on the objective of creating, in view of the embodiment according to U.S. Pat. No. 3,685,499, a hydraulic adjusting device where a rotation of the secondary part relative to the primary part can take place with little or no hydraulic pressure adjusting angles.
This objective is achieved by the effective direction of the piston as well as the arrangement and development of the transfer members connected with this piston. In the particular embodiment shown in FIGS. 1-3, the flexible connector, which effects circumferential rotation of the second any part with respect to the primary part is comprised of a chain linkage attached to the primary part of the transmission by means of a bolt through one link and positioned with respect to the secondary part of the transmission in such a way that the linkage rests on a lever which is pivotally attached to the secondary part. By these arrangements, operation of the hydraulic timing adjustment arrangement is achieved at a low pressure, such as the engine oil pressure, because the radial movement of the piston as well as the swivel movement of the lever is supported by the centrifugal forces occurring at an increasing speed of the internal-combustion engine.
Further, objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawing(s) which show, for purposes of illustration only, an embodiment constructed in accordance with the invention.